The bushings are in between the bolts that bolt the rack to the frame. But you say the rack itself does not move at all, then I would think the bushings are OK. If the bushings were bad, the rack would move around before steering your wheels.

I still say, grab ahold of the boot and see if the rack is actually moving before it steers the wheels. You may not be able to see it unless you grab ahold of it and feel for it.

88 4R, 350 V8, R150 5 speed Sold <...uot; />
97 4R, stock, daily driver
98 Sienna, kid and dog hauler, wife's ride